Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductor layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allow more components to be integrated into a given area. These smaller components require techniques for forming smaller features that are closer together than previous technique permit.
One technique providing features for 32 nm and smaller device fabrication procedures is self-aligning spacers. A mandrel layer is patterned, and a spacer layer is grown on the mandrel layer. The spacer material on the sidewalls of the mandrel layer remains after removing the mandrel layer, and the spacers are used as a mask to pattern a lower layer.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.